\documentclass[a4paper,twoside]{book}
\usepackage{listings}
\usepackage{amsmath}
\usepackage{listings}
\usepackage{epsfig}
\usepackage{amsmath}
\usepackage{color}
\definecolor{grayLines}{gray}{0.6}
\definecolor{grayText}{gray}{0.3}
\usepackage{multirow}
\usepackage{wasysym}
\usepackage{gensymb} 
\usepackage{longtable}

\usepackage{alltt}
\usepackage{geometry}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{ae}
\usepackage{lastpage}
\usepackage{fancyhdr,lipsum}
\usepackage{titlesec}
%% 20.08.2016 LP
%%Workaround to fix a bug in titlesec in Ubuntu 16, erase when not needed. 
\usepackage{etoolbox}

\makeatletter
\patchcmd{\ttlh@hang}{\parindent\z@}{\parindent\z@\leavevmode}{}{}
\patchcmd{\ttlh@hang}{\noindent}{}{}{}
\makeatother
%%End of the workaround.
\usepackage{pdfpages}
\usepackage{draftwatermark}
\usepackage{hyperref}


\pagestyle{fancy}
\fancyhf{}
\fancyhead[LE,RO]{\thepage}
\fancyhead[CE]{\emph{XC User's Manual}}
\fancyhead[CO]{\slshape \footnotesize{\leftmark}}


\setlength\parindent{0pt}
\title{XC User's Manual}
\author{XC Structural Engineering}
\date{\today}

\begin{document}
\maketitle
\lstset{language=Python}          % Set your language (you can change the language for each code-block optionally)
\setcounter{secnumdepth}{4}
\setcounter{tocdepth}{4}
\tableofcontents
\listoftables

\input{envirmt.tex} %environments definition
\input{varbl.tex}  %Latex variables definition

\input{introduction.tex}

\input{model_components/model_components.tex}


\input{materials/materials}

\input{model_components/elements}

%\input{model/model}

\input{loads/loads.tex}

\input{solution/solution.tex}

\input{materials/verificationSections.tex}

\input{roughCalculations/roughCalculations.tex}

\appendix
\chapter{Generation of combinations to consider in the structural calculation}

\input{appendixACombinations/load_combinations_body}

\begin{thebibliography}{77}	% start the bibliography 
\small				% put the bibliography in a small font
\input{bibliography.tex}
\end{thebibliography}


\end{document}
